Automatic siren silencing device for false alarms

Abstract

An automatic siren silencing device for false alarms, for use in an alarm system having a siren driver which powers a siren. A microcomputer monitors pulse signal characteristics of the siren driver, including duration of pulses and number of pulses, and compares these characteristics with predetermined pulse signal characteristics stored in a memory. A relay coil is energized by the microcomputer, controlling a relay switch which disconnects the siren from the siren driver when the pulse signal characteristics are indicative of a false alarm thereby silencing the siren. A user means is provided to adjust the predetermined pulse signal characteristics. Power to the microcomputer is provided by a capacitor, charged by the signal of the siren driver, whereby no battery or dedicated external power supply input is required. Indicator lights and a piezo element inform a user of siren silencing, and indicate the types of false alarms detected.

1. An automatic siren silencing device for false alarms, for use in an alarm system having a siren driver and a siren, said siren driver powering said siren, comprising:
 a means for powering said device;  
 a means for interrupting power from said siren driver to said siren;  
 a means for maintaining memory of predetermined switching characteristics;  
 logic means for determining whether switching characteristics of said siren driver are equivalent to said predetermined switching characteristics;  
 said logic means being operatively connected to said siren driver for detecting said switching characteristics;  
 said logic means also being controllably connected to said means of interrupting power;  
 said logic means interrupting power from said siren driver to said siren when said logic means determines that said switching characteristics are equivalent to said predetermined switching characteristics.  
 
   
   
     2. The device as recited in  claim 1 , wherein said means for powering is a means for storing electrical charge, said means for storing electrical charge being electrically coupled to said siren driver, said means for storing electrical charge being charged from the power of said siren driver whereby a dedicated external power supply or a battery requiring replacement is not required for said device to operate. 
   
   
     3. The device as recited in  claim 2 , wherein said means for storing electrical charge is a capacitor. 
   
   
     4. The device as recited in  claim 1 , wherein said means for powering is the signal from said siren driver. 
   
   
     5. The device as recited in  claim 1 , wherein said means for powering is a power input connector whereby power may be supplied by a battery or a power supply drawing power from a standard alternating current electrical outlet. 
   
   
     6. The device as recited in  claim 1 , wherein said means for interrupting power is a relay. 
   
   
     7. The device as recited in  claim 1 , wherein said predetermined switching characteristics include a plurality of switching parameters. 
   
   
     8. The device as recited in  claim 7 , wherein said plurality of switching parameters includes a number of siren driver pulses value. 
   
   
     9. The device as recited in  claim 7 , wherein said plurality of switching parameters includes a duration of siren driver pulse value. 
   
   
     10. The device as recited in  claim 7 , wherein said plurality of switching parameters includes a time window of siren driver pulses value. 
   
   
     11. The device as recited in  claim 7 , wherein said plurality of switching parameters includes a siren power interruption delay value. 
   
   
     12. The device as recited in  claim 1 , wherein said switching characteristics include a plurality of siren driver on-times and siren driver off-times whereby duration of siren driver pulses and a count of said siren driver pulses can be determined by said logic means. 
   
   
     13. The device as recited in  claim 1 , wherein said switching characteristics include a duration of siren driver pulse value. 
   
   
     14. The device as recited in  claim 1 , wherein said logic means is a computer. 
   
   
     15. The device as recited in  claim 1 , further including a user interface means for user changeable program setting of said predetermined switching characteristics whereby false alarm detection characteristics of said device can be customized by a user. 
   
   
     16. The device as recited in  claim 15 , wherein said user interface means is a means of operatively connecting said device to a general purpose computer whereby said general purpose computer sends said predetermined switching characteristics to said means for maintaining memory. 
   
   
     17. The device as recited in  claim 16 , wherein said means of operatively connecting is a serial interface connector. 
   
   
     18. The device as recited in  claim 15 , wherein said user interface means is a plurality of switches. 
   
   
     19. The device as recited in  claim 1 , further comprising means for displaying operational status of said device, said means for displaying operatively coupled and responsive to said logic means, said operational status established according to said determination of equivalence between switching characteristics and said predetermined switching characteristics. 
   
   
     20. The device as recited in  claim 19 , wherein said means for displaying is a plurality of indicator lights. 
   
   
     21. The device as recited in  claim 1 , further comprising means for generating an audible signal in increments of varying duration, said means for generating operatively coupled and responsive to said logic means, said increments of varying duration established according to said determination of equivalence between switching characteristics and said predetermined switching characteristics. 
   
   
     22. The device as recited in  claim 21 , wherein said means for generating is a piezo element. 
   
   
     23. The device as recited in  claim 1 , further including a means to reset said logic means whereby memory of said switching characteristics is reset and said logic means reconnects power from said siren driver to said siren. 
   
   
     24. The device as recited in  claim 1 , further including a relay, a means for a user of said device to connect to the switch of said relay, said logic means controllably connected to the coil of said relay, the switch of said relay is switched by said logic means whenever power from said siren driver to said siren is interrupted by said device whereby the switch of said relay forms a normally open or normally closed loop that may be used by said user for a plurality of miscellaneous useful functions in said alarm system. 
   
   
     25. The device as recited in  claim 1 , further including a warning horn, said warning horn electrically connected to said means for interrupting power whereby said device includes said warning horn in an integrated unit that automatically silences when said integrated unit detects a false alarm. 
   
   
     26. The device as recited in  claim 1 , further including an alarm system controller, said alarm system controller electrically connected to said means for interrupting power whereby said device includes said alarm system controller in an integrated unit that automatically stops driving said siren when said integrated unit detects a false alarm. 
   
   
     27. A siren disrupter for false alarms, for use in an alarm system having a siren driver and a siren, comprising:
 a relay having a relay coil and a relay switch;  
 said siren derives power from said siren driver through said relay switch;  
 said relay switch disconnects power to said siren when said relay coil is activated;  
 a computer is controllably connected to said relay coil;  
 said computer is operatively connected to said siren driver to sense the signal of said siren driver;  
 said computer compares pulse signal characteristics of said siren driver with predetermined pulse signal characteristics;  
 said predetermined pulse signal characteristics stored in a memory;  
 said computer disconnects power to said siren when said computer determines that said pulse signal characteristics are equivalent to said predetermined pulse signal characteristics.  
 
   
   
     28. The siren disrupter as recited in  claim 27 , further including a capacitor, said capacitor being electrically connected to said siren driver, said capacitor being charged from the power of said siren driver, said capacitor powering said computer. 
   
   
     29. The siren disrupter as recited in  claim 27 , further including a user interface means for user changeable program setting of said predetermined pulse signal characteristics. 
   
   
     30. A method of automatically interrupting power from a siren driver to a siren in an alarm system in the event of a false alarm, the method comprising the steps of:
 continuously sensing the signal of said siren driver;  
 comparing pulse signal characteristics of said siren driver with predetermined pulse signal characteristics to determine if any of said predetermined pulse signal characteristics are met;  
 interrupting power from said siren driver to said siren if said predetermined pulse signal characteristics are met.  
 
   
   
     31. The method in  claim 30 , wherein said predetermined pulse signal characteristics include a number of pulses value. 
   
   
     32. The method in  claim 30 , wherein said predetermined pulse signal characteristics include a pulse duration value. 
   
   
     33. The method of  claim 30 , wherein said method further comprises the step of generating an alarm if any of said predetermined pulse signal characteristics are met whereby a user is notified of a false alarm with indicator lights or a tone generator. 
   
   
     34. The method of  claim 30 , wherein said method further comprises the step of reconnecting power from said siren driver to said siren when said predetermined pulse signal characteristics are no longer met. 
   
   
     35. The method of  claim 30 , wherein said method further comprises the step of being programmed by a user.